Mine supporting structure



Sept. l, 1953 K. GERLAcH MINE SUPPORTING STRUCTURE Filed July 28, 1949 iL il INVENTOR F5644 mam; @ERLAGH m' A'fTUaRNEY Patented Sept.- l, 1953MINE SUPPORTING STRUCTURE Karl Gerlach, Moers, Germany Application July28, 1949, Serial No. 107,202 In France July 30, 1948 (Cl. (S1-45) 1Claim.

The invention relates to a mine supporting structure of metal props andgirders for mines which are being Worked, in which structure the girdersare movably connected at their adjoining ends. The individual irongirders are constructed in the shape of short profiles or sections whichare at rst connected with the preceding girders to be freely supportedthereby and which, as the working progresses, are supported by one ormore props. Since in that type of mine lling construction the girdersare at rst installed to be freely supporting, their joints, by means ofwhich they are movably connected, are exposed to considerablemountain-pressure which is effective on the long lever arms of thefreely supported girders.

In this connection it is known to effect the shifting of the girders bymeans of a tensioning device which swings them into the desired positionand retains them there until they are released during the furtherrobbing of the mine. In these known mine supporting constructions anendeavor was made to provide the tensioning arrangement with itsabutments as far as possible from the joint bolts in order to providefavorable leverage conditions for the joints and the tensioning device.This, however, entailed the disadvantage that in the installation of thegirders they could no longer be brought in over the link or joint boltsbecause the distance between the joints and the abutments of thetensioning devices was too great. It was, therefore, necessary toprovide special auxiliary link or joint axles around which the girderswere swung when being installed. Aside from these disadvantages, anddespite providing a large distance between joint bolts and abutments ofthe tensioning devices it was necessary to reinforce the profiles of thegirders in the vicinity of the joints, both at the bottom and at thetop. As a result of the increase of the cross section of the girders inthe region of the joints a further disadvantage resulted in that thegirders could no longer be brought to bear against the roof along theirfull lengths.

The invention relates to a mine supporting structure using props |andgirders in which the abutting ends of the girders are connected with oneanother in a manner to be movable around a pivot joint and under thecontrol of a tensioning device, and it is the purpose of the inventionto eliminate all disadvantages of the known mine supportingstructures ofthis type. In accordance with the invention this is substantiallyachieved in that the abutments for the tensioning and locking means arearranged outside of the cross section of the girder profile,particularly at the under-side of the girders in the form of rigidextensions. This makes it possible to make the lever arms relativelylarge with respect to the effective forces, while, at the same timeforming that portion of the joint of the girders which is disposed belowthe prole relatively small in size, thus permitting the supporting propto be installed closely adjacent the joint. It is, moreover, possible toconstruct the joint, the abutments and the tensioning arrangement asstrong as the loads require, because the construction proposed inaccordance with the invention affords considerable liberties withrespect to the dimensioning of these parts.

In accordance with the invention the tightening of the tensioning andlocking arrangement is advantageously arranged in the direction of theaxles of the girders, which makes it possible to keep the spacerequirement for the arrangement of the abutments of the tensioning andlocking device as small as possible. As a Whole, the tensioning meanscan be arranged in accordance with the invention substantially in themanner of a pair of tongs or cutting nippers. Furthermore, it isadvantageous in accordance with the invention to construct the joints ofthe girders in such a manner that the abutments of the tensioning meansare arranged away from the interengaging ends of the girders andprovided With full cross sectional planes so that the cross key is notsubject to flexure. It is furthermore advantageous in accordance withthe invention to arrange the tensioning means with its abutments so faraway from the cross section of the profile that the girder is allowed toswing around the joint possibly as much as The tensioning means can thenbe formed particularly advantageously as `a cross key and the connectingplanes of the cross key and of its abutments may be spherically shapedto insure full contact of the cross key in any angular position of thegirders. This form of construction simultaneously insures against thecross key falling out.

In accordance with the invention it is also possible to design the crosskey in such a manner, as to shape and dimensions, that it acts as asafety or deforming element against overloading of the girders. On theother hand, it is also possible to provide ya special plastic or elasticdeforming element in the region of the abutments of the tensioningmeans.

It is still a further essential proposal in accordance with theinvention to take into account the particular kind and distribution ofthe loads to which the profiles of the beams are exposed in a minesupporting structure for working mines such as is the subject of theinvention. The fundamental proposal of the invention is to form thegirders substantially as bodies of equally distributed strength. Thatcan be achieved, for example, in that the abutment is formed as areinforcing enlargement of the profile cross section at the end whichadjoins the intersection in the region of greatest stress of the braceproles. This enlargement decreases 4gradually to the normal profilecross section'of'the beams.

In accordance with the inventiony the girders with joints and abutmentscan furthermore be produced as unitary structures produced by pressing,forging or casting, and, for example also out of aluminum orcorresponding other light metal alloys. On the other hand, embodimentsof the invention are possiblein which the Yconstruction is by means ofwelding together separate parts.

, Other advantageous particulars in accordance with `the invention areshown in the drawings which Villustrate examples of the invention and inwhich: l

Fig. 1 is ay girder connection `for mine supporting* structures inaccordance with the invention in-side elevation; 4 g s Fig. 2 is a planview of the structure according to Fig.- 1;

Fig. 3 illustrates a further embodiment of the invention, Yand Fig. lshows a mine filling structure including two props and three girders.

In accordance with Figs. 1 and 2` thegirders I and 2 Vare connected withone another for swinging movement around the joint -bolt or trunnion 3and are underthe control of a tensioning and locking device 4 in theform of a cross key or wedge. Theend of the girder 2 engages the end ofgirder I in the manner of a fork 5 as shown (Fig. 2).

Fig. 1 reveals that the cross wedge 4 and its abutments and 'I atthevends of girders vI and 2, respectively, are arrangedl outside of theprole ofthe cross section'of the girders I and -2 vand below the joint3. Thehcontact surfaces-between cross wedge 4 always makes a completeVcontact with the abutments 5 and 1, even when the girder 2 is' indifferent angular positions with-respect to vgirder I. yThis insuressimultaneouslyagainst disengagement of the cross wedge." The uppersideof the girders I Vand 2, on the other hand is formed to becontinuous and is thus disposed in a plane. It should be noted that thejoint bolt orpin 3 is positioned laterally of the girders andsubstantially in lateral alignment with -the Aneutral plane of thegirders.

The abutments 6 and -1 vand the vwedge `4 are arranged so far away fromthe profile vcross section of thegirders I'and 2 that the girders I and2can pivotY around the joint 3to the extent of an -angle as greatas-QO".y Thus, it is possible in the installation to first hang thegirder r2 'onto beam I, whereupon it is swung into `a horizontalposition andnally it can be retained in the desiredposition'byfthe'insertion of the cross wedge 4.V Thetightening of-the'crosswedge 4 iseiTective in the r"direction'of the longitudinalaxes of the girdersfl and 2 'and encountersralso exteriorly of the-,fork5 at 'theabutment 'I full and continuous engagement planes so 4that itis-not exposed to bending stress inthe directiony of vitselongitudinalaxis. As a whole the joint in accordance with the invention is formed inthe manner of a pair of cutting nippers, and besides the advantagesalready mentioned it is also possible to shape the cross wedge 4 as toform and dimensions in a manner that it acts as a safety or deformingelement, i. e. in a manner that it is already deformed as a result ofthe mountain pressure before girders I and 2 are taxed beyond thestrength of their pro'le cross sections. For this purpose the crosswedge 4 may have a -rounded shape, such as shown particularly in Fig.

3. It ispossible, on the other hand, to insert a Vparticular'plastic orelastic deforming element in ,theI regionof the abutments 6 and 1.

As a whole, the drawings show, particularly in I` Fig. 4' that in aminesupporting structure in accordance with the invention the joint connecitionfoiE the girders may not only be formed with advantageous lever armsand strong individual parts to meet the requirementsas to loads, butprovidesalso for a particularly compact form-of construction, so thatthe supporting prop 9 for the freely carriedgirder 2 can be disposed inthe immediate proximity ofthe joint bolt 3. Since, however, the countermoments in the area of this support are especially great, afurtherimportant feature of the inventionprovides for the. abutment l at theend of the girders Vwhich adjoin the overlaps to riseinto a reinforcing.enlargement 8 of the profile crosssection ofthe beams whichsubstantially strengthensthe girders inthe vicinity of theprop tovwithstand the moments arising there. The reenforcernent 8 .graduallydecreases to the normal profile cross section. In this manner it ispossible in accordanceA with the invention tolform the girders withrespect to the moments encountered in a manner `that they approximatebodies of approximately evenly distributed strength. It is alsovpossible to provide the'girder I-(Fig. 4l which is exposed-to theIgreatest loads withy an additionalreinforcement II) which is shown indotted lines.

As shown in the drawings the girders with the joint portions andabutments consist `advantageously-ofi'a unitary `conformation which canbey producedby forging, pressing or.casting,.par ticularly also out oflight metals, but it is also possible to produce themin the form of avwelded structure.

rll'iepossibilities of the invention are, however, not exhausted by the.embodiments described, although the fundamental concept of providing theAabutrnents. lfor .the tensioning and .locking means for a `pivotedgirder connection below. the pivot point can berealized in otherdesirable forms. Furthermore, the concept of the invention to`especially reenforce the cross section of the girders in the region ofthe greatest moments of strain by a. speoialconcentration of.material atthe bottom side of the-girders and thus to form the girdersapproximately asbodies of. equally distributed strength is ofvindependentsignicance and may be. employed independently'of theformation of the connection joint on. which the= invention lis. based,vparticularly in all mine filling-constructions where freely carrying.girders are atnrstsupported atonly'one side by .means of a prop.

Having now" described my inventiony with Vreference to the" embodimentsillustrated, what I claim is:

A 'miner'oof supporting 'structureacornprising generally flongitudinallyaligned girders, each girder fcomprising a Arst projecting element atone end thereof, spaced projecting elements at the other end thereof,said girders being pivotally interconnected with said rst projectingelements of each girder being received between said spaced projectingelements of an adjacent girder by a pin positioned laterally thereof andsubstantially in lateral alignment with the neutral plane of saidgirders, each of said girders having a depending projection adjacent itspoints of pivotal connection to adjacent girders and presentingabutments facing corresponding abutments on said adjacent girders, andWedges in -Wedging engagement with the facing abutments of said girdersand extending transversely of said -girders.

KARL GERLACH.

References Cited in the file of this patent UNITED STATES PATENTS 10Number Name Date 2,510,593 Mechling .Tune 6, 1950 2,554,210 Pierre May22, 1951

